Life might be more orderly and easy to understand if biology worked just like this:

People come in one of two sexes, male or female. This is determined by chromosomes, and XX means female, and XY means male. Males have penises and testicles—which are all similar in appearance and curvature and size—that secrete testosterone in similar proportions. This testosterone is metabolized, functions similarly in all men, and causes them to have similar amounts of musculature and deep voices and certain amounts of facial and back hair, and to act in particular ways because of this hormone. It causes their brains to develop and make them behave in ways that are “manly.”

These men are attracted to women, specifically women who look normal, a result of the fact that they definitionally have exactly and only two XX chromosomes, which cause them to develop clitorises and uteri and breasts and ovaries that produce estrogen and other hormones that prompt cycles of growth and the shedding of the uterine lining, and who predictably bear children when sperm meets egg. All these features develop and function the same way in all women who are normal—whose amounts of hormones make their bodies look and feel more or less the same, and whose brains develop and function in a way that is female and that consigns them to certain roles in social hierarchies.

That’s the middle-school health-class version. Like any simplistic model, it’s presented as an introduction. Most 11-year-olds do not yet know about enzymes and cell biology, have barely begun to consider the complex differences between humans, and aren’t ready to grapple with the social implications of the simplistic dichotomy. Plus, it would be impossible to go into greater depth without the class snickering every time the teacher said “ambiguous genitalia” or “micropenis.”

The paradigm is somewhat similar to saying that automobiles come in two forms: cars and trucks. This is a worldview that is easily challenged by the existence of SUVs and station wagons—neither of which would suddenly disappear, even if government officials tried to make up a definition that excluded them.

Yet this is the paradigm that the Department of Health and Human Services is preparing to use to define gender, according to a memo reported in The New York Timestoday: “The agency’s proposed definition would define sex as either male or female, unchangeable, and determined by the genitals that a person is born with … Any dispute about one’s sex would have to be clarified using genetic testing.”

Much is being made of the proposed policy’s relevance to the 1.4 million Americans who identify as transgender, as the Timesstory did, reporting that the proposal has an eye to “defining transgender out of existence” and was prompted in part by “pro-transgender court decisions.” The implications go beyond this even. There is also the scientific implausibility and fundamental impossibility of imposing such a definition. Just as it’s overly simplistic for a government to define all people based purely on chromosomes or physical appearance, many genotypic and phenotypic varieties exist outside the proposed binary.

The agency proposes to define gender “on a biological basis that is clear, grounded in science, objective and administrable.” Which would indeed be ideal at a bureaucratic level. Even looking no further than the maternity ward or doula’s chambers, though, human biology does not abide by the rules laid out for us in sixth grade.

Though they have long been anathema to talk about, there are many thousands of variables that affect gestation and fetal development—some influenced by epigenetic factors generations before conception—that lead to a spectrum of outcomes for any given infant. These can include sex-chromosomal anomalies (XXY or XYY, for example), the irregular functioning of enzymes that activate or metabolize hormones, or the blocking of binding sites where hormones typically act, which effectively could lead an XY person to develop female genitalia (known as Swyer syndrome) or an XX person to develop male genitalia. Thousands of infants each year are born with “ambiguous genitalia” that can look something like a penis and a clitoris (which are fundamentally structurally analogous, spongy tissue consisting of a crus and glans that become engorged and hypersensitive during sex).

There are two statistical peaks in the distribution of infant outcomes that roughly accord with the states described in middle school, but there is also everything in between and on other sides. Entire textbooks are written on the wide variety of ways sex hormones can manifest during fetal development and throughout life. The exact number of infants born in the domain known as “intersex”—who, for any number of reasons, do not clearly fit into one of the two sexes based on genitalia or chromosomes or both—is difficult to know because for many years, such people were “normalized” at birth by default.

The idea of changing infant genitalia surgically at birth has become an area of intense ethical debate in recent decades, and it stands to only become more relevant, as infants born with ambiguous genitalia are becoming more common—or, at least, increasingly documented—which some evidence suggests is due to exposure to environmental pollutants that affect fetal development.

Human-rights organizations have campaigned against genital surgeries for intersex infants, and in 2017 three former U.S. surgeons general published a report that argued, “While there is little evidence that cosmetic infant genitoplasty is necessary to reduce psychological damage, evidence does show that the surgery itself can cause severe and irreversible physical harm and emotional distress.” A policy from HHS that puts infant genitalia at the center of a person’s identity runs directly counter to this medical advice.

While the relevance of this discussion is not going away, some public intellectuals such as the author Michael Pollan have suggested that bringing this policy memo to the forefront of national conversations is savvy politics just before the midterm elections. “Don’t take the bait!” he tweeted this morning. The implication is that the intention of the administration is to stir a culture war that, rife with misinformation and fearmongering, will rally Trump’s base around the idea that liberals want to destroy the concept of men and women and, so, God and family, desecrating the very idea of America.

Looked at another way, the policy could just as well raise objections among people concerned about “big government” and defending individual rights. Scientific implausibility aside, this is a federal agency proposing widespread genetic testing and keeping records of citizens’ genitals. This is a proposal by the government imposing an expectation that everyone look and act in one of two ways, and that everything in between is somehow not right—an aberration, an anomaly, a flaw, a problem, a disease—rather than a marvel of the natural world, a way that humans survive and thrive not despite but because of our complexity as a species.

Even those who believe a simplistic dichotomy does and should explain the world—regardless of the millions of people who exist as evidence to the contrary—should see reason to question the Americanness of government imposing such a rigid prescription on everyone.

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